MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, Beijing; National Research Center for Information Science and Technnology, Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Artificial Intelligence, State Key Lab of Intelligent Technology and Systems, Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China.
State Key Lab for Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; Wuxi Environmental Monitoring Centre, Wuxi 214121, China.
Sci Total Environ. 2019 Jun 15;669:29-40. doi: 10.1016/j.scitotenv.2019.03.087. Epub 2019 Mar 8.
In aquatic ecosystems, both phytoplankton and bacteria play pivotal roles. Based on 16S rRNA gene sequencing, considerable research focused on phytoplankton colony attached and free-living bacteria has revealed the close relationship between them, and indicated that the entire bacterial community mediates crucial biogeochemical processes in aquatic ecosystems. However, our understanding of their distribution patterns and response to environmental factors remains poor. Besides, picocyanobacteria, which were omitted from attached bacteria analysis, were reported to be important in cyanobacterial blooms. To explore the spatiotemporal variation of the entire bacterial community with their driving environmental factors and detect the relationships among them, we collected 61 water samples spanning one year and the entire Lake Taihu regions for surveying the entire bacterial community. Our results indicated: 1) seasonal variation of the bacterial community composition was stronger than spatial variation due to the clearly seasonal variation of Microcystis, Synechococcus (pico-cyanobacteria) and other bacteria (Actinomycetales, Pirellulaceae and Sphingobacteriaceae); 2) the spatial distribution of the bacterial community showed that different phyla were dominant in different regions; 3) the bacterial co-occurrence networks varied seasonally and were dominated by Microcystis, ACK-M1, Chthoniobacteraceae, Synechococcus, Pirellulaceae and Pelagibacteraceae; 4) phytoplankton density, chlorophyll a, water temperature and total nitrogen were the major factors that drove the spatiotemporal variation of bacterial community composition. This study revealed the seasonal succession and spatial distribution of the entire bacterial community in Lake Taihu, providing new insights into the relationship between water bloom-forming cyanobacterial species and other bacteria, and their response to environmental factors in eutrophic freshwater ecosystem.
在水生生态系统中，浮游植物和细菌都起着关键作用。基于 16S rRNA 基因测序的研究主要集中在浮游植物群体附着和自由生活的细菌上，揭示了它们之间的密切关系，并表明整个细菌群落介导了水生生态系统中至关重要的生物地球化学过程。然而，我们对它们的分布模式和对环境因素的响应的理解仍然很差。此外，被排除在附着细菌分析之外的微微型蓝藻被报道在蓝藻水华的形成中很重要。为了探索整个细菌群落及其驱动环境因素的时空变化，并检测它们之间的关系，我们收集了跨越一年的 61 个水样，并对太湖地区进行了整个细菌群落的调查。我们的结果表明：1）由于微囊藻、聚球藻（微微型蓝藻）和其他细菌（放线菌目、拟杆菌科和鞘脂杆菌科）的明显季节性变化，细菌群落组成的季节性变化强于空间变化；2）细菌群落的空间分布表明，不同的门在不同的区域占主导地位；3）细菌共生网络随季节变化，以微囊藻、ACK-M1、硫杆菌科、聚球藻、拟杆菌科和Pelagibacteraceae 为主；4）浮游植物密度、叶绿素 a、水温、总氮是驱动细菌群落组成时空变化的主要因素。本研究揭示了太湖整个细菌群落的季节性演替和空间分布，为富营养化淡水生态系统中水华形成蓝藻物种与其他细菌之间的关系及其对环境因素的响应提供了新的见解。
